Scleral clip and procedures for using same

ABSTRACT

A method and clip for treating presbyopia and/or open angle glaucoma in which the sclera is supported or reinforced, while substantially maintaining the spacial relationship between the ciliary muscle and the lens. The method includes making an incision in the conjunctiva to gain access to the sclera overlying the ciliary muscle. The Tenon&#39;s capsules are moved laterally to expose the sclera, and the sclera is extended outwardly. A clip, or series of clips, is provided having two closeable arms for engaging the outwardly-extended sclera therebetween. The arms of the clip are closed on the sclera so as to grasp a portion of the sclera, and then the Tenon&#39;s capsules are slid over the clip and the conjunctiva is closed.

[0001] The present invention is directed to a surgical method fortreating vision disorders, such as presbyopia and/or glaucoma, and tothe associated devices used in conjunction with the method.

BACKGROUND OF THE INVENTION

[0002] Presbyopia is a vision disorder associated with aging resultingfrom the failure of the accommodation mechanism of the eye. Theaccommodative mechanism is driven principally by parasympatheticinnervation of the ciliary smooth muscle. In the non-presbyopic eye,this causes the muscle to slide forward in a unified manner and producesan inward movement of the muscle. The result is a reduction in thediameter of the ciliary muscle collar that instigates a series of eventsleading to an ability to see near objects clearly.

[0003] While it is clear that the capsular elasticity of the lens of theeye, i.e., the ability of the lens capsule to mold the lens, diminisheswith age, the precise cause of presbyopia remains the subject of debate.

[0004] Presbyopia is most frequently treated by the use of readingglasses, bifocals, and progressive multi-focal contact lenses. However,the inconveniences associated with eyeglasses and contact lenses haveprompted investigation into, and the development of, surgical techniquesaimed at correcting presbyopia.

[0005] One such method is anterior ciliary sclerotomy (“ACS”). ACS isbased on the theory that accommodation results primarily from ciliarybody contraction, with the resulting forward movement of the lens. Itsunderlying rationale is based on the observation that the lensconstantly grows throughout life, gradually crowding the posteriorchamber and eventually preventing full function of the ciliarybody/zonular complex. The “crowded” state causes the reduction of lenspower change with attempt at accommodation. ACS utilizes a series ofsymmetrical radial, partial-thickness scleral incisions to attempt tomake more room for the ciliary body—which in turn allows more space forthe lens—by expanding the globe in the area of the ciliary body.However, this procedure has many potential complications, ranging frominfection and hemorrhaging to perforation, which could result in retinaldetachment, iris injury or prolapse.

[0006] Another proposed method for surgical reversal of presbyopia isbased on the theory that presbyopia results when the distance betweenthe ciliary body and the equator of the lens and its capsule becomesless with age as a result of the normal growth of the lens. Thus, underthis theory presbyopia is treated by increasing the effective workingdistance of the ciliary muscle. This is accomplished by implanting aseries of scleral expansion bands just below the surface of the scleraand outside the cornea. The bands stretch the sclera so that thediameter of the circle describing the intersection of the plane of theciliary body with the sclera is slightly increased. See, U.S. Pat. Nos.5,354,331 and 5,489,299 to Schachar. However, at least one study hascalled into question the accuracy of the theory on which scleralexpansion surgery is premised. See, Mathews, “Scleral Expansion SurgeryDoes Not Restore Accommodation in Human Presbyopia,” Opthamology, Vol.106, No. 5, May, 1999, pages 873-877. This study concludes that, ifscleral expansion surgery does alleviate presbyopia, an explanationother than the restoration of accommodation needs to be found. Schacharalso believes that his scleral expansion bands may have utility in thetreatment of primary open-angle glaucoma by restoring the level of forcewhich the ciliary muscle exerts on the trabecular meshwork, thus openingthe drainage pores and relieving the intra ocular pressure (IOP).

[0007] Regardless of the theory employed, there is a need for correctingpresbyopia without the use of eyeglasses or contact lenses through arelatively safe and simple procedure that is easily reversible. There isalso a need for treating glaucoma that is safe, effective, and simple.

[0008] Accordingly it is the principal object of the present inventionto provide a surgical method for the treatment of ophthalmic disordersthat can be ameliorated by supporting or reinforcing the scleral.

[0009] More specifically, it is an object of the present invention toprovide a surgical method for treating presbyopia and/or glaucoma.

[0010] It is a further object to provide such a method that has areduced potential for complications and is easily reversible.

[0011] It is a still further object of the invention to provide a clipuniquely suited for use in the treatment of presbyopia and/or glaucoma.

SUMMARY OF THE INVENTION

[0012] These objects, as well as others which will become apparent uponreference to the following detailed description and accompanyingdrawings, are accomplished by a method for treating presbyopia andglaucoma in which the sclera is supported or reinforced, while thespacial relationship between the ciliary muscle and the lens issubstantially unchanged. Specifically, the method includes making anincision in the conjunctiva to gain access to the sclera overlying theciliary muscle. The Tenon's capsules are moved laterally to expose thesclera, and the sclera is extended outwardly. A clip, or series ofclips, is provided for grasping the outwardly-extended sclera. The clipincludes a series of teeth or similar structures that engage a portionof the sclera, thus securing the clip thereto, and then the Tenon'scapsules are slid over the clip and the conjunctiva is closed.Preferably, four such scleral clips are applied to the sclerasubstantially equally spaced about the lens between the medial,inferior, lateral and superior rectus muscles. When applied to thesclera, the clips serve to prevent the sclera from buckling undertension applied by the ciliary muscle when trying to accommodate the eyeto near vision.

[0013] In another aspect of the invention, a scleral clip is providedfor applying to the sclera. The clips have a length of typically between4 to 5 mm, and no longer than approximately 6.0 mm, so as to fit betweenadjacent rectus muscles. The clips are provided with means, such asteeth or spurs, for grasping—but not penetrating through—the sclera.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is a horizontal sectional view of an eyeball.

[0015]FIG. 2 is an anterior view of the eye showing the extrinsic eyemuscles.

[0016]FIG. 3 is a simplified diagram showing two scleral clips attachedto an eye.

[0017] FIGS. 4-14 are views of clips of various configurations to beapplied to the sclera in accordance with the present invention.

DETAILED DESCRIPTION

[0018] The method of the present invention is based upon a theory forthe cause of presbyopia different from those set forth above.Specifically, presbyopia is caused by the failure of the ciliary body toadjust the lens diameter in order to focus images onto the retina forclose objects. The ciliary muscles change the lens diameter by using thesclera as a support or fixation structure. As the sclera of the eyeweakens due to age, the ciliary muscles lack the support needed in orderto alter the lens diameter for focusing on close objects. Thus, in orderto allow the ciliary muscle to alter the lens diameter to see closeobjects, the sclera must be supported or reinforced. Accordingly, amethod is provided that utilizes a unique clip for reinforcing thesclera, so as to form a stronger and more stable support for the ciliarymuscles. In effect, the sclera is strengthened, and the ciliary musclesare then able to again function properly to provide near vision.

[0019] It is believed that the method and its associated clip may alsobe advantageously used for the treatment of open angle glaucoma.Glaucoma, like presbyopia, is an age-related disease and is caused by abuildup of fluid pressure in the eye which damages the optic nerve. Overtime, glaucoma destroys peripheral vision, thus shrinking the field ofvision. In a healthy eye, the fluid produced by the ciliary tissuessurrounding the lens is drained out of the eye by a series of drainagecanals around the outer edge of the iris. With age, because the ciliarymuscles lack support, they are less capable of maintaining thesedrainage canals in an open condition to allow free drainage of fluid. Bytensioning the sclera according to the present method, the support isprovided for the ciliary muscles, and the tissues of the eye thatprovide for drainage are stretched, thus reducing blockage of the fluiddrainage canals and facilitating the drainage of fluid from the eye.

[0020] With reference to FIG. 1, there is seen a simplified sectionalview of a human eye 10 having a lens 12 contained within a lens capsule14. The ciliary body and ciliary muscle 16 are connected to the lenscapsule 14 and also to the choroid 18. The sclera 20 overlies thechoroid 18 and, at the front of the eye, the ciliary muscles 16, andterminates in the scleral spur 22 at the cornea 24 of the eye. Theconjunctiva 26 surrounds the cornea 24 and overlies the bulbar sheath(or Tenon's capsule) 28 which in turn, overlies the sclera 20 on thefront of the eye. Blood is supplied to the sclera by arteries in thesuperior, inferior, medial and lateral rectus muscles 30, 32, 34, and 36respectively, best seen in FIG. 2.

[0021] In the method of the invention, the eye is treated by firstmaking a series generally linear incisions (such as incisions 38 in FIG.2) in the conjunctiva 26 to gain access to the sclera 20. Preferably,prior to making the incisions, a generally standard preoperativeprocedure is performed that includes marking the limbus and cornea at10:00, 2:00, 5:00 and 8:00 with violet blue to indicate the location ofthe incisions.

[0022] The incisions 38 are made radially outwardly from the cornea soas to generally bisect the area between the adjacent rectus muscles(e.g., between the superior and medial rectus muscles 30, 34 as shown bythe incisions 38 in FIG. 2). For each incision 38, an initial incisionis made to dissect to the conjunctiva 26, bypassing the Tenon's capsule28. Then the incision is deepened to open the incision into theepisclera, creating an incision of from 3 to 7 mm in length in theepisclera. The incision is opened and, if necessary, the Tenon's capsule28 is then moved laterally to expose the sclera 20.

[0023] The sclera 20 is then extended outwardly either mechanicallywith, e.g., a forceps, or by the application of a vacuum. A clip 40 isapplied to the outwardly-extended sclera so as to put the sclera 20under tension. The Tenon's capsule 28 is then reapposed over the clipand the conjunctiva 26 closed. No suturing is needed as the conjunctiveself seals. The procedure is then repeated for each of the markedquadrants so that four clips are applied to the eye equally spaced aboutthe cornea 24 between the adjacent rectus muscles.

[0024]FIG. 3 is a simplified drawing showing two clips 40 attached tothe eye 10. The clips 40 grasp the sclera overlying the ciliary body 16adjacent the iris 39. The applied clips 40 have a generally low profile,closely adhering to the curvature of the eye, thus providingreinforcement to the sclera.

[0025] With reference to FIGS. 4-9, the clips for use in the procedurecan take many different forms. In general, it is contemplated that theclip 40 will have an overall dimension of approximately 1.5-2.5 mm inheight (h), 0.4-0.6 mm in thickness (t) and no longer than 5.0-6.0 mm inlength (l). The size of the clip is constrained by the distance betweenthe adjacent rectus muscles. Specifically, the intent is to have theclip fit between the rectus muscles, so as to not impede the flow ofblood to the eye through the arteries in the rectus muscles. Thus,instead of a single clip having a length of approximately 5.0 to 6.0 mm,a series of clips can be used the sum of whose total length fits betweenthe adjacent rectus muscles. Of course, it is anticipated that the useof a single clip of the appropriate length will allow the procedure tobe performed more easily and quickly.

[0026] As can be readily appreciated, the procedure can be simplyreversed by merely again gaining access to the sclera by making anincision in the conjunctiva over the clip, moving the Tenon's capsule toexpose the clip, and then removing the clip. No incision into the sclerais required.

[0027] In each of the FIGS. 4-9, the clip 40 includes two arms 42, 44joined together for relative movement to each other. On the insideportions of the clip are teeth, serrations, spurs, barbs, fingers,points 46 or other structures or projections for engaging and securelyholding or gripping the sclera to the arms of the clip as it is affixedto the sclera. The teeth 46 are sized to engage the sclera, but not beof a size or configuration to penetrate through the sclera (which mightcause erosion of the sclera). Consequently, the teeth 46 may be as smallas 20-80 μm. The clips are originally in their “open” position and then“closed” on the sclera with a forceps or other applicator, the clipsremaining in their closed condition in the absence of an external forcebeing applied to separate the arms of the clip. It is contemplated thatthe arms of the clips will be closed on the order of 10 to 15 degrees.This should prolapse the uvea and move the sclera outward approximately0.5 mm, for a total of 2 mm if four clips are applied. This willincrease the amplitude of accommodation, thus reversing the effects ofpresbyopia. This outward movement of the sclera should also increase theangle of the canals of Schlemn, thus increasing the aqueous flow anddecreasing the intra-ocular pressure, to ameliorate the effects ofglaucoma. The clips 40 may be made of any biocompatible material,including tantalum, polymethyl methacrylate (PMMA), and, preferably,titanium, that has sufficient deformability and resiliencecharacteristics to permit the clip to be “opened” and then remain closedwhen applied to the sclera. Turning to FIG. 4, a first embodiment forthe scleral clip 40 is shown in which each of the legs 42, 44 is bowedinward so as to impart some resiliency to the clip 40. Each leg 42, 44also includes a series of teeth 46 for gripping into the sclera. Thescleral clip of FIG. 5 is similar to that of FIG. 4, except resiliencyis imparted to the clip 40 by having the legs 42, 44 bow outwardly.

[0028]FIG. 6 shows a further embodiment of a clip 40 that comprises acentral portion in the shape of a rectangle folded along a diagonal,with a tooth 46 at each of the lower corners. A pair of staple-likemembers also having teeth 46 depend from the opposite ends of therectangular portion so as to provide further means for gripping thesclera.

[0029]FIG. 7 illustrates a clip embodiment similar to FIGS. 3 and 4except that the clip 40 includes a resilient band 48 that connects oneleg to the other. The band 48 serves to keep tension on the legs 42, 44of the clip when the teeth engage the sclera.

[0030]FIG. 8 shows a clip 40 that has a spider-like configuration with aplurality (4 shown) of legs depending from a central body, each legterminating in a tooth 46.

[0031]FIG. 9 shows a clip 40 similar to those of FIGS. 3, 4 5 and 6,except that central portions of the clip 40 are removed to give it afork-like appearance.

[0032]FIG. 10 is a further embodiment of a scleral clip 40 according tothe present invention that is similar to the clip of FIG. 7, except thatit does not include the resilient tensioning band. The clip 40 includesan indentation 50 in the center of each arm 42, 44 for cooperation witha tensioning instrument for application of the clip. Also, the teeth 46have a length of 200 μm and are rounded, beveled, or blunted, so as tonot present a sharp edge that could penetrate the sclera. The clip maybe provided with a latex-free silicone polymer or acrylic coating,preferably white in color, on the outer or upper surface thereof inorder to make the clip less conspicuous when attached to the eye.

[0033]FIGS. 11a and 11 b are a perspective view and end view,respectively, of a further embodiment of a clip 40. This embodiment issimilar to that in FIG. 4, except that the arms 42, 44 are not bowed,but are substantially flat. The clip 40 is preformed so that the anglebetween the two arms is approximately 175 degrees, so that, when appliedto the sclera and the arms are closed 10 to 15 degrees, the anglebetween the arms is between approximately 160 to 165 degrees. This angleprovides for a clip that, when applied more closely approximates thecurvature of the eyeball. This is likely to be perceived by the weareras more comfortable, and may also reduce any erosion of tissue thatoverlies the applied clip. The angle of the teeth 46 to their respectivearms 42, 44 is approximately 90 degrees.

[0034]FIG. 12 is a perspective view of a clip 40 similar to that ofFIGS. 11a, 11 b, except that the end portions of the arms 42, 44 arerelieved inwardly at 52. This reduces the portion of the clip 40 that,when attached to the eye, extends beyond the radius of curvature of theeye, to achieve the benefits of wearer comfort and reduction of tissueerosion discussed above.

[0035]FIG. 13 is a further embodiment of a clip 54 in accordance withthe present invention. The clip 54 has the same overall dimensions asthe clip disclosed above, i.e., approximately 3 to 5 mm by 5 to 6 mm, soas to fit between adjacent rectus muscles. However, the clip is oval orround in shape and has a central opening 56 enclosed by a continuousouter portion so that the clip 54 has a ring-like appearance. This clipis applied to the sclera by prolapsing the sclera through the centralopening in the clip by mechanical means, such as a twist hook orforceps, or by the application of a vacuum. One or both of the centralopening 56 or outer edge 58 may be provided with teeth 60, which aresimilar to teeth 46 described above, for securing the clip to thesclera. Further, the teeth may be bent out of the plane generallydefined by the clip so that they more firmly grip the sclera. Withreference to FIG. 14, the teeth on the outer edge or periphery 58 may bebent downwardly an angle α from between approximately 90 degrees toapproximately 135 degrees, while the teeth on the central opening orinner periphery 56 are bent downwardly an angle β between approximately20 degrees to 45 degrees.

[0036] The clip 54 is generally flat, with little or no angle betweenthe two arms or sides 62, 64, as defined by the center line through theclip, thus providing a very low profile. Preferably, the clip 54 issufficiently thin so that it conforms to the natural shape or curvatureof the eye.

[0037] Thus, a method and a clip for performing the method have beenprovided that fully meet the objects of the present invention. While theinvention has been described in terms of a preferred method and clip,there is no intent to limit the invention to the same. Instead, theinvention is defined by the scope of the following claims.

What is claimed:
 1. A clip for attachment to an eye having a pluralityof rectus muscles, scleral tissue, and a curvature, the clip being sizedto fit between adjacent rectus muscles, being adapted to be secured tothe scleral tissue, and having a central open portion enclosed by acontinuous outer portion through which the scleral tissue extends whenthe clip is applied thereto, the clip closely conforming to thecurvature of the eye.
 2. The clip of claim 1 wherein the clip has anouter periphery and an inner periphery, the inner periphery defining thecentral open portion of the clip.
 3. The clip of claim 2 furthercomprising a plurality of teeth sized and configured to attach the clipto the sclera without penetration through the scleral tissue.
 4. Theclip of claim 3 wherein the teeth are between approximately 20 to 80 μmin length.
 5. The clip of claim 3 wherein the teeth are located on theouter periphery of the clip.
 6. The clip of claim 5 wherein the teethare bent downwardly from the clip between approximately 90 degrees toapproximately 135 degrees.
 7. The clip of claim 3 wherein the teeth arelocated on the inner periphery of the clip.
 8. The clip of claim 7wherein the teeth are bent downwardly from the clip betweenapproximately 20 degrees to 45 degrees.
 9. The clip of claim 3 whereinthe teeth are located on both the inner periphery and the outerperiphery of the clip.
 10. the clip of claim 9 wherein the teeth on theouter periphery are bent downwardly between approximately 90 degrees toapproximately 135 degrees and the teeth on the inner periphery are bentdownwardly between approximately 20 degrees to approximately 45 degrees.11. The clip of claim 2 wherein the clip is sufficiently thin to conformto the curvature of the eye.